利用电导检测器离子色谱建立了氰根的分析方法,考察了该分析方法的检测下限、线性范围、标准误差(RSD)以及加标回收率。在高频热解设备中对神府煤和稻草进行了快速热解实验,利用NaOH溶液吸收法将热解气中的HCN转化为氰根离子,利用所建立的检测方法对氰根进行定量。结果表明,信噪比为3时该分析方法的检测下限为0.01 mg/L,在0.1-50 mg/L范围内线性关系良好,标准误差(RSD)小于3%,加标回收率为90%-105%。对HCN吸收液样品进行检测时发现氰根与其他杂质离子分离效果较好,3次重复实验的重现性良好。所建立的HCN吸收方法和氰根检测方法能够满足煤和生物质热解时HCN生成率的考察要求。
A CN-ion analysis method was established using conductivity detector ion chromatography,and the detection limit,standard error and recovery rate of standard additions were investigated.Rapid pyrolysis of Shenfu coal and rice straw was carried out in a high frequency furnace,and the HCN in pyrolysis gas was absorbed and converted to CN-ions using NaOH solution,then the CN-ions were analyzed by the established method.Research results show that the detection limit is 0.01mg/L when signal-to-noise ratio is 3,there is a good linear relationship in the range from 0.1 to 50 mg/L,the standard errors are lower than 3%,the recovery rate of standard additions is 90%-105%.Experiment also shows that CN-ions can be effectively separated from other impurity ions,and fine repeatability can be obtained.The proposed HCN adsorption method and CN-analysis method can meet the investigation requirements of HCN formation rate during coal and biomass pyrolysis.